Clinical Presentation and Outcomes of Acute Pericarditis in a Large Urban Hospital in the United States of America.

BACKGROUND: Acute pericarditis is the most common presentation of pericardial diseases. Although generally benign, complications such as constrictive pericarditis, cardiac tamponade, and recurrence can occur. RESEARCH QUESTION: What are the clinical factors associated with adverse outcomes in acute pericarditis? STUDY DESIGN AND METHODS: We used an informatics-based search engine to search for International Classification of Diseases codes related to pericardial disease between January 1, 2009 and November 14, 2018 and then extracted clinical information, including only patients meeting the European Society of Cardiology criteria for acute pericarditis. We then evaluated the predictive value of clinical characteristics for adverse outcomes (cardiac tamponade, constrictive pericarditis, failure of therapy, recurrences, or death). RESULTS: We identified 240 patients with a first episode of pericarditis (51 [34-62] years, 56% males and 50% white). Pericarditis was determined to be idiopathic in 126 (53%) cases and related to cardiac injury in 79 (33%). During a median follow-up time of 179 (20-450) days, 82 (34%) patients experienced at least one adverse outcome. Subacute presentation was an independent predictor of adverse outcomes. Patients with postcardiac injury pericarditis had a lower incidence in the composite of failure of treatment and recurrence (13% vs 26%; P = .022) compared with patients with idiopathic pericarditis. Troponin I measurements were obtained in 167 patients (70%). Elevated troponin I levels were associated with lower incidence of recurrences (4% vs 17%; P = .024) and of the composite outcome (13% vs 36%; P = .004). INTERPRETATION: Acute pericarditis is associated with at least one adverse outcome in 34% of patients. Subacute presentation and idiopathic etiology are associated with higher incidence of adverse outcomes, whereas elevated troponin I levels identify a group with reduced risk of recurrences.